John t



(No Model.)

J. T. DEMP-STER.

- 'ELEOTRIG LAMP SOCKET. No. 443,746. Patented Dec. 30, 1890.

" llllll UNITED STATES PATENT OFFICE.

JOHN T. DEMPSTER, OF SUMMIT, NEW JERSEY, ASSIGNOR TO BERGMANN &

COMPANY, OF NEW YORK, N. Y.

ELECTRIC-LAMP SOCKET.

SPECIFICATION forming part of Letters Patent No. 443,746, dated December 30, 1890.

Application filed Kay 24, 1890.

To aZZ whom it may concern.-

Be it known that I, JOHN T. DEMPSIER, a subject of the Queen of Great Britain, residing at Summit, in the county of Union and State of New Jersey, have invented a new and useful Improvement in ElectricLamp Sockets, of which the following is a specification.

My improvement relates to sockets employed with incandescent electric lamps.

The invention consists in improved circuitconnections for the socket, andin certain features of construction which will be hereinafter fully described and claimed.

In the accompanying drawings, which illustrate the invention, Figure 1 shows a side view of a lamp, and below the lamp a crosssection of the socket, the two parts of the socket being separated. Fig. 2 shows a side elevation of the socket, the two parts of the socket being separated. Fig. 3 shows a side view of the lower part of the socket at right angles to the view in Fig. 2, and Fig. at is a plan view of the socket.

The upper section of the socket consists of three parts-the outer metal shell or sleeve 1, provided at its lower end with a screw-thread or other fastening means 2, and preferably provided at its top with a bead 3. lVithin this shell is an insulating-lining 4, preferably of vulcanized fiber. Within this layer of insulation is a second metal'sleeve 5, extending partially through the outer sleeves and terminating at the bottom in a flange 6. In manufacturing this part of the socket a sheet of metal is rolled onto a sheet of the fiber, the screw-thread being impressed on both sheets. They are then bent into cylindrical shape and inserted into the outer tube, and are properly cemented in place.

The lower section of the socketconsists of a cup-shaped cap 7, having the screw-threaded flange 8 and the extension 9 for connection with a light fixture or bracket. \Vithin the cap is supported an insulating-block, preferably of vulcanized fiber. This block in its preferred form is cylindrical at its base, with a segment cut away at 10. The block may be held in place by screws passing through the bottom of the cap. On the side of the block which has been cut away are supported two Serial No. 362,989. (No model.)

metal contact-pieces 11 12, secured in place by screws or otherwise. These pieces are bent to extend over the top of the insulating-block, as clearly shown in Figs. 3 and 4. The ends of the springs are preferably, though not necessarily, left a little above the face of the block, so that they may act as springs when the parts are in use.

The wires from the lighting-circuit pass through extensions 9. One wire is connected to contact 11 and the other to contact 12. When the two sections of the socket are put together, flange 6 will bear on the spring end of con tact 11, and contact 12 will occupy a portion of the central space within the flange. When the lamp is screwed into its socket, the metal sleeve 13 on the lamp-base will make intimate contact with the sleeve 5, which, as we have just seen, bears on contact 11. The central terminal lat 0f the lamp will bear on the other contact 12, thus completing the circuit from the line through the filament of the lamp.

Instead of connecting the upper and lower sections of the socket by means of the screwconnection shown, it is evident that a bayonetjoint connection or other suitable locking means may be employed.

In the construction above described the parts are very simple and of such construction that they cannot well get out of adjustment, and there is no electrical connection between the exposed portion of the socket and the screw-threaded sleeve into which the lampbase, which is connected with the filament, is screwed. The circuit is complete independent of the outer sleeve.

Having thus described my invention, what I claim is 1. The combination, in an electric lamp socket, of a metal sleeve, a second metal sleeve within the same and insulated therefrom, terminating in a flange, an insulating-block insertible into the outer sleeve and carrying a contact co-operating with the flange, and a second contact. substantially as described.

2. The combination, in an electric lamp socket, of a metal sleeve with insulating lining, a central metal sleeve shorter than the first and terminating in a flange, an insulating-block insertible into the outer sleeve and 100 Within the same and insulated therefrom, terminating in a flange, an insulating-block insertible into the outer sleeve and carrying a contact co-operating with the flange, a second contact, said block being supported in a cap, and means for locking the cap to the sleeve, substantially as described.

This specification signed and witnessed this 18th day of April, 1800.

JOHN T. DEMRJTER. Witnesses:

J OWN W. MCGHIE, JNo. F. GEIDEL. 

